Arrow star Stephen Amell refuses to dismiss the possibility that Batman might one day appear in the Arrowverse - the shared universe made up of most of the superhero shows on The CW. While such an event seems unlikely, given Warner Bros. record of being historically protective when it comes to the depiction of DC Comics' most popular superhero on television, it would not be the most unlikely occurrence in the history of the Arrowverse.
The question of when, if ever, Batman might appear in the Arrowverse is one that has been asked more frequently in the wake of the announcement that Ruby Rose will be starring in a new Batwoman series. The new show is poised to spin out of this year's Arrowverse crossover event, Elseworlds, and is already one of the most highly anticipated television shows of 2019. While it's entirely possible for the character of Kate Kane to be introduced independent of Bruce Wayne despite the two being cousins in the comic books, it would simplify matters considerably in the future if the creators of the various Arrowverse series didn't have to dance around the Batman family of characters and concepts as they have in the past.
Comic Book reported on an impromptu Facebook Q&A, where Amell addressed the Batman question. One fan asked if Batman or Green Lantern - both characters who have been hinted at existing in the Arrowverse without actually making an appearance - would ever appear on Arrow. Diplomatically, Amell replied, "I would never say never."
While Amell's response is far from dismissive, the decision is hardly one he can be expected to influence much, even in his position as the star of Arrow. It wasn't until Arrow's sixth season that the series was allowed to mention Bruce Wayne by name, as part of a joke regarding the billionaire playboy being as likely a candidate for the secret identity of Green Arrow as Oliver Queen. Arrow was also forced to kill off all members of their version of the Suicide Squad and abort their plans for introducing Harley Quinn into the Arrowverse, due to Warner Bros. plans for the characters in the movies. Ironically, similar plans for Batman in the movies prevented Bruce Wayne and Batman from being used in the series Smallville, resulting in Oliver Queen and Green Arrow being used in their place.
On the other hand, while it seems unlikely Warner Bros. will change their policy regarding Batman in the Arrowverse, similarly unlikely things have occurred before. The studio has been equally wary about Superman being used in a supporting role on television, yet he was allowed to appear in several episodes of Supergirl's second season, and is scheduled to appear again in Elseworlds. As Amell says, it's not impossible for Batman to appear on Arrow, though it now seems more likely he might make his Arrowverse premiere in Batwoman.
Source: Comic Book